Since the focus is being shifted towards welcoming new players better, one aspect that I think would be huge is facilitating the player's stats and gear collected in offline mode into online mode.

Having the option to have an 'online' integration of the campaign would be ideal. For example, when choosing the offline campaign button, the player could initiate something like:

1) Click's offline realm button
2) Get a prompt asking "Would you like to enter online mode features? Your gameplay will be tied to the server, but you will have access to your limbo stash + invade/ally features"
3a)If No, go to offline menu like normal
3b)If yes, Just load up the server and have the equipment and ally/invade notifications pop up as they would if you were online (though you can keep it to the offline campaign menu to not overwhelm them with the bevy of online features/modes)

and that's it! Now, when players exit the wizard training when they click the single player campaign as instinct will push em to, they'll now have access to all of the good stuff that makes the realms work as good as they do online. You can just change the 'offline campaign' to 'Single Player Campaign' to reflect the changes.

Another bonus to this is that it could increase online activity. I noticed that when i look at steamcharts for current players that their is quite a large amount playing the 'offline' mode in comparison to the players in the online lobby. This might encourage some online activity, even if just in the form of realm activity and loot progression.